Roll drive



1933- E. FITZGERALD El AL l,923;360

ROLL DRIVE Filed Feb. 12, 1951 Patented Aug. 22, 1933 warren STATES normDRIVE 7 Edward Fitzgerald and Raymond M. Gleason,

1 Franklin, Ohio Application February 12,1931. Serial Natures 7 Claims.(01. e249) This invention relates to roll drives for press rolls and thelike such as are used for example in paper making machinery.

One object of the invention is the provision 5 of a compensatingfriction drive for press rolls and the like, which provides forsubstantially no slipping between the paper web on the web carrying feltand the roll with which it cooperates.

Another object of the invention is the provision of a compensatingfriction drive for a pair of cooperating rolls, one of which is drivenfrom a suitable source of power, drive means being provided for theother roll so arranged as to have a yielding adjusting means equalizingthe peripheral speed of this other roll with the felt speed.

A further object is the provision of a roll drive of the charactermentioned in which the upper roll is operated by a gear drive tending torotate it at a slightly greater peripheral speed than the lower roll,the drive means includin an adjustable friction device.

Other objects and. advantages of the invention will be apparent from thefollowing description, the appended claims and the accompanying drawing,in which,

Fig. 1 is'an' elevationalview, partly in section, of a pair ofcooperating rolls havingdrive means embodying the present invention; 7

' Fig. 2 is an end view thereof; and

Fig. 3 is 'a sectional view of another slightly different embodimentof'the invention;

Paper making machines and the like employ power press rolls, and thelike, running inpairs, one usually on top of the other, between which anendless felt 'is drawn. The felt serves to pick up' the paper fibersorto carry aweb that ultimately forms a paper sheet. exceedingly costlyitem and are subject to very great wear. due to slippage occurringbetween the roll and the felt; Ordinarily one of the rolls, usually thelower roll, is driven from a suitable source of power and the upper rollis rotated by the felt itself. ,Thusthe driving force tending to movethe feltalcng is applied only to the lower surface of the felt, by thelower roll, and as the upper side of the felt serves as a driving mediumfor the upper roll, it will be apparent that the felt will be pulled,torn, and Worn so that its life may be only several weeks. While thispulling and tearing action takes place principally on the lower surface,it is also present the upper surface on which the paper web rests, assufii cient power must be supplied to the upperroll These felts are an.

face, to rotate this upper roll. The resulting slippage between thepaper web and theupper roll necessarily roughens and pulls the topsurface of the web. F I v If both of the rolls are positively driven asby being intergeared together the two rolls will move at exactly thesame peripheral speed if the'ratio of the speeds of rotation of thedriving gears correspond exactly with the ratio of the diameters of thetwo rolls, but such an arrangementpulls the feltalong bythe applicationof power to both the upper and lower sides of the felt, and the slippagebetween the upper roll and the paper web objectionably'roughens theupper surface of the paper web. Furthermore, one roll may be a littlelarger in diameter than the other so if the two rolls are gearedtogether'by gears of equal size one roll will have a slightly greaterperipheral speed than the other, resulting of course in additional wearand tear of the-feltand paper Web surfaces. Even though originally thetwo rolls maybe of exactly the same size, it is frequently necessary toresurface the rolls as they become worn. The rolls ordinarily have brassor rubber surfaces and when wear takes place in one or both of the rollsit becomes necessary tochan ge the size of the gears and. to turn downworn rolls. y In accordance with the invention set forth in thisapplication, which isa continuation' in part of our prior applicationfor Letters Patent, Serial No. 461,518Qfi1ed June 16, 1930, all of theabove mentioned disadvantages are obviated, and drive means are providedfor the rolls so that friction between the paper web and the roll itengagesis obviated. This improves the quality of the paper and increasesthe life of the felts. .It also pre vents the corrugating of the, softerroll which might occur if the two roll shafts are positively Y gearedtogether, thus increasing the life of the 95 rolls, and prevents feltpicking, that is "the paper sticking to the felt when the'machine isrunning at high speed. The inventionis' applicable to rolls engaging asingle felton which the paper web rests, or to rolls engaging-top Ibetween them; g

Referring more particularly to the drawing by, reference numerals andfirst with reference to and bottom felts which carry the paper web:

and 11 of'a paper making machine, or the'like,

are mounted respectively on shafts'l2 and '13,

the rolls being covered with a layer of rubber, brass, or othersuitable'isurfacing material. -'I'he.:

upper roll 11 constitutes the driven ro1l,:- while 91" ed against thefriction grip disk 20.

the roll is the driver roll. As shown each of these rolls are of thesame diameter although they could be of different diameters if desired.The shaft 12 is mounted on a suitable bearing 14, and is driven by aclutch 15 and drive shaft 16 connected to a suitable source of power.Mounted in locked engagement with the shaft 12, through the medium of akey 17 or the, like, is a gear 18 which meshes with a similar gear 19carried by the shaft 13 in a manner to be hereinafter described.

Mounted on the shaft 13 is a friction grip,

disk 20 provided with a hub 21 which is fixed to the shaft by means ofthe key 22. The shaft 13 of the roll 11 is supported by a suitablebearing 23. The gear 19 is bushed as at 24 and is mounted on the hub 21of the friction grip disk 20 to turn freely thereon, and is adapted tohave one face thereof engage the face of the friction grip disk 20, theother face of the gear being shown flush with the edge of'the hub 21. I

Threaded in the hub 21 areaplurality of circumferentially spaced bolts.25, spaced from the shaft 13 and parallel therewith, and extending foradistance beyond the end, of the shaft. Seated on the remaining portionof the shaft 13 is a friction grip disk 20 which is provided withcircumferentially spaced openings through which the bolts -25freelypass, thefriction grip disk 2G being freely slidable on the shaft13 and bolts 25. The abutting faces of the gear 19 and friction gripdisksZOand 20 are provided with adjacently positioned circular grooves26 in which are positioned circumferential friction shoes 2'? made ofmetal or other suitablefriction material, these shoes being providedbetweenthe gear and disks, and attached to either the gear. or thedisks, if desired. 'Mounted on the bolts 25 and abutting the heads 25thereof is a plate 28 provided with a central adjusting set screw 29which has a lock nut 29. Spaced inwardly of the plate 28 is anadditional plate 30 which is slidably mounted on the bolts 25 and whichengages a coil compression spring 31 surrounding the bolts 25 and seat-The coil spring 31 functions to resiliently force the friction gripdisks 20 and 20 against the faces of the gear 19, the degree of pressurebetween the gear faces and the friction grip disks, being regulated bymeans of a set screw 29 as will be readily apparent from Fig. 1 of thedrawing. Y

The twogears 18 and19 may drive the rolls at the same peripheralspeedbut preferably are so constructed and arranged as to tend-to drivethe rolls 1,0 and 11 at'rslightly different periphe For example, whenthe rolls 10 and 11 are of the same diameter, the gear 18 may be of thesame 1 pitch diameter as the gear 19, but will have one tooth ,more thanthe gear=19. If the rolls 10 and 1 1 are considerably different indiameter, the

drive gears 18 and 19 maybe so formed, as to pitch diameters and numberof teeth, that the peripheral speed of the upper roll will be slightlygreater than that of thelower roll, providing no friction obtains in thefriction device provided in the drive means which interconnects the rollshafts. The compensating friction drive provided in the drive means forthe rolls, however, may be readily adjusted so that the amount of slippage that occurs inthe friction device, between the gear 19 and thefriction grip disks,--will be just sufficient to effect a driving of theupper roll at exactly the same lineal speed as the speed of the felt orother traveling web that is moving between the two rolls. No pullingforce is therefore applied to the paper web by the upper roll and thereEwill be no tearing or shredding action on the upper surface of the feltor on the paper 'web. This, of course, permits the felts to be used overcomparatively long periods of time before they need to be replaced. Letus assume that 12 horsepower is required by the drive of the two rolls11 and 12. The roll 11 and its drive might absorb 3 horsepower in thecompensating friction and gear drive bearings, etc. None of this 3horsepower would be supplied to the felt or supplied from the felt. Theremaining 9 horsepower would be supplied to the roll 10 and its driveand only part of this, let us say 6 horsepower, would be transferred tothe lower sur-- face of the felt to pull the felt along, while3horsepower :is absorbed in the bearings, etc., of the roll 10. Consider,however, what takes place in the constructions now in use, in which onlythe lower roll is driven while the upper roll-is rotated by the felt,acting as a belt. 9 horsepower might be supplied bythe lower roll to thelower surface of the felt and-3 horsepower would then besupplied by theupper surface of the felt or the paper web on it to the upper roll toovercome bearing friction, etc., of the upper roll. In those cases wherethe upper and lower rolls are positively geared together to run at thesame speed and when the power is supplied to the felt equally on itsupper and lower surfaces it will be apparent that the friction thatobtains between the upper roll and the upper surface of the paper webwill have a harmful roughening and tearing effect on the web that isentirely overcome by the present invention. 7 I

Fig. 3 shows a preferred embodiment of the invention. As shown in thisfigure the upper roll 11 of a pair of cooperating rolls of a papermaking machine corresponding to the rolls 10 and 11 shown in Fig. 1, isdrivenby the gear 35 through a friction clutch, the gear 35 meshing witha gear 36 fixed to the shaft of the lower roll in the same manner as setforth in Fig. 1. The roll 11 in this case may be of .the same diameteras the lowerroll, and the gear 35 would have one less tooth than thegear 36 so that the upper roll 11' tends to operate at a surface speedslightly greater than the peripheral speed of the lower rollywith whichit cooperates. The friction clutch-comprises the opposite sides of thegear 35, the friction surface 3'7, and the friction hlf grip disks 41and 42; The friction grip disk 41 is preferably keyed to the end of theroll shaft .43 and rotatably supports the hub portion of the gear 35 andalso carries the hub portion of the friction gripdisk 42. The twofriction grip disks are provided. with interengaging lugs43 and 44 sothat the two disks 41 and 42 rotate in unison,

Threaded into the end portion 45 of the friction gripdisk 41 is a rod46, provided coaxially with the roll shaft and projecting through a bore47 in the end plate portion of the friction disk 42.

A coil compression spring 48 bears at one 'end against the outer side ofthe end plate and casing 51 can be taken off and the position of thespring retainer 49 adjusted along the rod 46 to provide the propercompression between the driving and driven members of the clutch. Theamount of compression may be so adjusted as to cause the peripheralspeed of the lower roll to be exactly in correspondence with theperipheral speed of the lower roll due to the compensating effect of theslippage obtaining between the gear 35 and the friction grip disks.

Preferably the friction surfaces 37 are oiled or lubricated and for thispurpose the friction grip disk 41 is provided with one or more'oilingnipples 54 so that the oil may be supplied to the friction surfaces. Asshown, the oil is supplied to the right-hand side of the friction diskand finds its way to the other side thereof and to the other frictionsurface 37 through holes 55, extending through the gear 35 and throughthe friction surfaces. preferably fixed in a suitable manner to the gear35. a

While the forms of apparatus herein described constitute preferredembodiments of the invention, it is to be understood that the inventionis not limited to these precise forms of apparatus, and that changes maybe made therein without departing from the scope of the invention whichis defined in the appended claims.

What is claimed is:

l. A compensating friction drive for press rolls comprising a driverroll, a driven roll, a drive gear rigidly attached to the shaft of thedriver roll, a

driven gear on the driven roll meshing with said driver gear, disksconcentric with said driven gear, friction members between said drivengear and said disks, and an oil supply coupling member on one of saiddisks, said gear having an oil passage from one disk to the other.

'2. A compensating friction drive forpress rolls of a paper makingmachinery comprising a driver roll, a driven roll, a drive'gear rigidlyattached to the shaft of the driver roll, a driven gear on the drivenroll meshing with said driver gear, and friction clutch means on saiddriven roll operatively connecting said driven gear with said drivenroll and constructed so as to provide for slippage during normaloperation, said friction clutch means comprising a friction grip diskhaving a hub rigidly mounted on the shaft of the driven roll, a slidablymounted friction grip disk, said driven gear being frictionally mountedon said. hub between said friction grip disks in frictional engagementtherewith, and adjustable resilient means for forcing said friction gripdisks yieldingly' against the opposite faces of said driven gear.

' 3. A compensating friction drive for press rolls of a paper makingmachinery comprising a driver roll, a driven roll, a drive gear rigidlyattached to the shaft of the driver roll, a gear on the driven rollmeshing with said driver gear, and friction clutch means on said drivenroll. operatively connecting it with said driven gear to permit rotationof said driven roll, said friction clutch means com- 4. A compensatingfriction drive for rollsof the 4,

The friction surfaces 37 are,

. the rolls operating at substantially the character described,comprising a driver roll, a driven roll, a drive gear rigidly attachedto the shaft of the driver roll, a gear on the driven roll meshing withsaid driver gear, a friction member fixed to the. shaft of thedriven-roll and supporting said driven gear for relative rotationalmovements thereon, a second friction member mounted coaxially with saiddriven gear and said first named friction member, said driven gear beingmounted between said friction members so as to be frictionally'clampedtherebetween, spring means acting to yieldingly press said frictionmembers together, means for adjusting the force of said spring, saidgears having such diameters and tooth number as to tend to drive thedriven roll at a slightly greater peripheral speed than the peripheralspeed of said driver roll if there is no slippage of the frictionmembers.

5. A compensating friction drive for rolls of the character described,comprising a driver roll, a'

driven roll, a drive gear rigidlyattached to the shaft of the driverroll, a gear on the driven roll meshing with said driver gear, afriction member fixed to the shaft of the driven roll and supportingmeans for. adjusting the force of said spring, said gears having suchdiameters and tooth number as to tend to drive the driven roll at aslightly greater peripheral speed than the peripheral speed of saiddriver roll if there is no slippage of the friction members, and ahousing enclosing said spring means and supported on one of saidfriction members in a readily detachable manner. I

6. A press roll drive for a paper carrying felt comprising a drivingroll, drive'means for said roll, a driven roll cooperating with thedriving roll to feed a paper carrying felt through the nip of the rolls,gearing for operating said driven roll from said driving roll,cooperating friction clutch elements incorporated between one of thegears and one of said rolls and constructed to provide for slippageduring normal operation, and adjustable yielding means for yieldinglygoverning the slippageof said friction clutch elements, said gearing,clutch elements and adjustable means providing for effective pullingoperation of both of same peripheral speed.

7. A press roll drive for a paper carrying felt comprising a drivingroll. drive means for said roll, a driven roll cooperating with thedriving roll to feed a paper carrying felt through the nip of the rolls,gearing for operating said driven roll from said driving roll,cooperating friction clutch elements incorporated between one of thegears and one of said rolls and constructed to provide for slippageduring normal operation, said gearing being constructed to drive thedriven roll at a slightly greater peripheral speed than the speed ofsaiddriving roll if there is no slippage of said friction clutch elements,and adjustable yielding means for yieldingly governing the slippage ofsaid friction clutch elements, saidgearing, clutch elements andadjustable means providing for effective pulling operation ofboth of therolls operating at substantially the same peripheral speed. EDWARDFITZGERALD. RAYMOND M. GLEASON.

